1. Field
The subject Invention is in the field of heavy nails and spikes, particularly spikes used for attaching railroad rails to railroad ties in conjunction with plates set between the rails and ties. The plates distribute the loads applied by the rails on the ties over a larger area.
2. Prior Art
In the prior art, at points along the rail, the rail is fastened to a plate and a tie by spikes which go into the tie through holes in the plate and the heads of these spikes engage the edges of the flanges of the rail, thus providing attachment of the rail at a point and partial attachment of the plate to the tie at the same point. Additional spikes are driven through holes in the plate that provide further attachment of the plate to the tie. The loads on the rails from wheels rolling on the rails are not vertical, so that there is a horizontal component of the loads, applied to the rail and tending to move it sidewise and also to roll it over since the load is applied some distance above the flanges of the rail. The rail is prevented from rolling over by a force couple comprising an upward force between a rail flange and the plate at the edge of one flange and a downward force applied by the head of a spike onto the edge of the other flange. The limit of the restraint to rolling over is determined by the distance between the edges of the flanges and the force required to pull the spike out of the tie. This limit is generally regarded as inadequate. Two prior art techniques for raising this limit are (1) use of serrations or threads to increase the force needed to pull the spike from the tie and (2) using a clip which attaches the flange to the plate when the clip is held in place by a spike which is located close to the edge of the flange but which fastens the plate to the tie. The clip and spike fit in a hole in the plate which is normally occupied by a spike alone. Therefore, the spike used with the clip is a special spike and smaller than the standard spike. This technique is taught in U.S. Pat. No. 4,354,634, issued to Kasuba et al. Clipping the rail to the plate shifts the burden of preventing roll-over to the plate and the spikes attaching it to the tie. Since the plate is wider than the flanges of the rail and the spikes holding the plate to the tie are farther apart than the spikes attaching the rail, the resistance to roll-over is significantly increased. However, the increase is limited somewhat by the lower strength and holding capability of the smaller spike. Also, the need for another loose part adds to increased inventory and handling costs. Further, the load is transferred from the rail flange to the plate by the clip which, because of the need to put the clip and the spike in the standard size hole, is not as strong as a spike.
In view of these facts the prime objective of the subject invention is to provide a railroad spike which attaches the flange of a rail to the plate on which the rail is supported and also attaches the flange and plate to the tie on which the plate is supported. A second objective is that the cross sectional area of the spike be roughly equivalent to that of a standard spike so that the spike which is the subject invention is approximately equal in strength to a conventional spike of the same class.